Obviously a recurring theme on this board is input on first time experiences and getting started.  I am a newbie, seeing my first provider 3 months ago.  Since then I've seen 5, while it seems a lot I'm still going through the trial phase and I'm still trying to find exactly what I like.  I thought it would be useful for me to recap what I've learned over the past few months.

Firstly, a recap of my experiences.  I realized from the beginning that I wasn't a 30 minute guy, so I opted for a 90 minute session.  I was extremely nervous, to the point that I couldn't perform.  My main problem was not enough comfort time prior to starting.  The next was a massage parlor girl, I've said it before it was great for what it was but it wasn't a GFE experience nor was it intended to be, I did it more to prove to myself that I could perform with a "stranger".  All went well and was enjoyable from a sexual perspective.  But I was looking for a bit more, something more intimate (which I expected).  I built an extra evening into a recent business trip and planned a 2 hour out-call session (she visited me) at my hotel with drinks before hand.  That did the trick, quite a bit of research paid off.  She met me at the hotel bar, our intended 30 minute drink lasted 90 minutes but she was very accomodating about "sharing" the cost of that time...as it turned out she absorbed all but about 30 minutes of the time as a freebie.  The next experience was with a smoking hot older provider on a in-call basis, I had planned 90 minutes but because she had availability I extended to 2 hours (with the appropriate compensation of course).  It was heaven, she was sweet, it was comfortable, and it was the best sex I ever had.  The most recent experience wasn't so great, for a few reasons, lack of sexual connection, a bit of a disappointing physical experience, etc...anyway, lesson learned.  So, what have I learned?  Read on:

1) Know what you like: Carefully read through the reviews available on TER, for instance, if you aren't a big talker and a few reviews hint that the provider is very talkative...just move on.  Forget the visuals and sexual reviews and pay attention to what you like.  If you have your ear talked off in the first 10 minutes the session will likely not recover.
2) Be realistic about the photos: I've never experienced a bait and switch but understand that most providers use professional photos.  The right lighting, make-up, computer effects, and angles portray the providers in the best possible light.  You will be seeing them in the au natural state...assume that a 9 in pictures will likely be a 7 in person.  I have been very very lucky in that with one minor exception I have not been disappointed with the physical appearance of the girls I've been with.
3) You aren't buying a BFF: Understand the providers do this day in and day out and a big part of their job is to make you feel like you are the only guy in the world.  DON'T LET IT GO TO YOUR HEAD!  Don't expect to carry on e-mail correspondence after the fact for more than just a cursory exchange to say thank you (which is recommended...send a nice "thanks for your time" message).
4) Time is money: You are exchanging money for time, just because a provider doesn't have something to do for the rest of the night doesn't mean she will spend that time with you for free.  Paying for 90 minutes means just that, don't expect that she will have nothing to do and will spend additional time "gratis".
5) They are just flesh and bone too: A good provider will make you feel like you are the only one but the reality is they have likely been with 2-5 guys the same day they will be with you.  Go easy...if you have it in your mind to "give it to them hard" understand that the other guys may have too...GO EASY!  Don't object if they want to use lube, make sure your nails are trimmed, be sure you have shaved your facial hair, and no means no...if you want to do anal and they object, go with it...don't sneak 2 fingers in during doggy...just because they are escorts doesn't mean they should be treated with disrespect.  You are paying money for their time, you aren't buying them for that time.
6) Study the providers website: You can most often find out everything you need to know about each girl.  The providers are each individual, some have certain limits while others don't.  Carefully read the FAQ and Etiquette sections and abide by the recommendations.  DON'T assume they are saying one thing but you will be different.

I hope this wasn't too rambling and I hope my advise and recap is taken as it is intended...as an insight from someone who might be in exactly the same situation as you.